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Cost Structure of IoT Connectivity Services

Written by Lu Lin

Paper category

Master Thesis


Computer Science




Thesis: NB-IoT To support a wide range of cellular devices and services, Narrowband Internet of Things (NB-IoT) is a licensed LPWAN radio technology standard released by 3GPP [33]. There are two other technologies in 3GPP Release 13, eMTC (LTE Cat M1) will enhance LTE, and EC-GSM-IoT aims to improve GSM. However, NB-IoT can be seen as a new track based on the existing 3GPP technology. Compared with other LPWAN technologies, the advantage of cellular solutions is that they have no duty cycle regulations because they operate on licensed frequency bands. In NB-IoT, in order to optimize the low-end market, LTE has added a new radio platform [34]. The goal of releasing NB-IoT is to provide lower cost and extended coverage (164dB) than eMTC. NB-IoT can also support long battery life (10 years) and massive devices (50,000 per unit). It has been optimized in certain areas, such as reduced data rate/bandwidth, mobility support, and further protocols. NB-IoT has 3 modes of operation: • Independent: Use independent carrier. It is deployed in a separate frequency spectrum of 200kHz. All transmission power is consumed at the base station to increase the coverage area [10]. • Guard band: Utilize unused resource blocks in the LTE carrier guard band. It is located at the same location as the LTE cell and shares transmission power. • In-band: Utilize resource blocks in common LTE carriers [34]. Broadband LTE and NB-IoT share transmit power at the base station. As for the characteristics of the physical layer in the OSI model (PHY), NB-IoT uses a narrowband and can support 180kHz. There are two modes for uplink, one is single tone and the other is multi-tone. But it does not support Turbo code or downlink. It also supports SFBC single transmission mode of PBCH, PDSCH, PDCCH. 3GPP is constantly trying to improve NB-IoT in the new version. It is said that it will be expanded to include positioning methods, multicast services, mobility, etc. [9]2.4 LTE-MLTE-M is one of the candidates to support M2M communication in Long Term Evolution (LTE) cellular networks. Many mobile operators and companies, such as Nokia, Ericsson and Qualcomm, have chosen LTE-M to provide IoT services by optimizing LTE. LTE-M is the abbreviation of LTE Cat M1. 3GPP previously released LTE Category 0 for MTC, and LTE-M has made improvements on this basis. LTE-M also supports long battery life (10 years), low equipment cost and extended coverage (155.7dB). One more thing, LTE-M provides variable rates, from 10kbps to 1Mbps, depending on coverage requirements [34]. The deployment of LTE-M is easier because it is based on the current LTE network. It can coexist with other LTE services in the same bandwidth and can be deployed in any LTE spectrum. Provides FDD, TDD and half-duplex (HD) modes [34]. The most convenient and cost-effective feature is that existing LTE base stations can be reused by simply updating the software. 2.5 EC-GSM-IoT EC-GSM-IoT, also known as EC-GSM, is another LPWA technology being developed by 3GPP. It is designed as an enhancement to GSM. At present, most GSM designs are reused, but some changes have been made to meet the requirements of LPWA [10]. GPRS/GSM equipment, extended coverage and variable rate. Compared with GSM/EDGE, it can support a large number of devices and improve security. EC-GSM-IoT provides new logical channels aimed at extending coverage and superimposing CDMA to increase cell capacity [34]. EC-GSM-IoT has been further enhanced in the 14th release of 3GPP. The radio interface enhancement function of EC-GSM-IoT is specified to support positioning. It improves the MCL by at least 3 dB for all low-power devices on the uplink. An alternative mapping for blind physical layer transmission for higher coverage levels is used. In fact, because EC-GSM-IoT is based on the GSM network, it can be updated through software. After the software is updated, support for new devices can be implemented in the existing GSM deployment [10]. 2.6 WiFi-HaLow In order to support IoT applications, the new Wi-Fi standard is also called WiFi-HaLow (or IEEE 802.11ah). ) By the Wi-Fi Alliance. Compared with the existing Wi-Fi standard, many MAC functions have been added to support a large number of devices, extended operating range and lower energy consumption [35]. In terms of its specifications, it can support up to 8,191 devices associated with an access point (AP). It operates at carrier frequencies below 1 GHz. It supports a transmission range of up to 1 km in outdoor areas. The data rate of WiFi-HaLow is higher than other LPWA technologies, reaching at least 100 Kbps. There is no doubt that it can be a cost-effective solution with extremely low energy consumption [35]. However, equipment operating in the sub-1 GHz ISM band must comply with the European maximum duty cycle limit of 2.8%. They can also support Liste Before Talk (LBT) and Adaptive Frequency Agility (AFA) functions [11]. In order to optimize long battery time and a large number of STAs, WiFi-HaLowespcially has designed some functions. It provides more efficient short frame format, short control/management, asymmetric and two-way transmission. It reduces power consumption through non-TIM operation, target wake-up time (TWT) mechanism, and extended sleep and listening intervals [36]. As we mentioned before, there is no existing method for IoT networks that can be used directly. We get this method by enhancing the existing methods of other wireless networks, and use it to get the results, divided into three parts, as shown in Figure 4. Scenario assumptions, network scale and cost structure calculations. Read Less